Fischer-tropsch processes using xerogel and aerogel catalysts by destabilizing aqueous colloids

Abstract

A process is disclosed for producing hydrocarbons by contacting a feed stream comprising hydrogen and carbon monoxide with a catalyst in a reaction zone maintained at conversion-promoting conditions effective to produce an effluent stream comprising hydrocarbons. The process is characterized by using a catalyst prepared by a method involving (1) forming a catalyst gel by destabilizing an aqueous colloid comprising (a) at least one catalytic metal for Fischer-Tropsch reactions (e.g., iron, cobalt, nickel and/or ruthenium), (b) colloidal cerium oxide, zirconium oxide, titanium oxide and/or aluminum oxide, and optionally (c) Al(OR) 3 , Si(OR) 4 , Ti(OR) 4 and/or Zr(OR) 4 where each R is an alkyl group having from 1 to 6 carbon atoms; and (2) drying the gel.

What is claimed is:  
     
       1. A process for producing hydrocarbons, comprising contacting a feed stream comprising hydrogen and carbon monoxide with a catalyst in a reaction zone maintained at conversion-promoting conditions effective to produce an effluent stream comprising hydrocarbons, wherein the catalyst comprises a catalytically active metal selected from the group consisting of iron, cobalt, nickel, ruthenium, and combinations thereof dispersed in a matrix material comprising a derivative of a destabilized aquasol comprising a colloidal oxide of a matrix metal selected from the group consisting of cerium, zirconium, titanium, aluminum, silicon, and combinations thereof. 
     
     
       2. The process of  claim 1  wherein the matrix material content of the catalyst is from about 99.9 to about 35 mole percent. 
     
     
       3. The process of  claim 2  wherein the matrix material content of the catalyst is from about 50 to 85 mole percent. 
     
     
       4. The process of  claim 2  wherein the matrix metal is selected from the group consisting of cerium, titanium, aluminum, and combinations thereof. 
     
     
       5. The process of  claim 4  wherein the matrix metal is a combinations of titanium and aluminum, and the atomic ratio of titanium to aluminum is from about 5:95 to about 95:1. 
     
     
       6. The process of  claim 1  wherein the catalytically active metal comprises from about 0.1 to 50 mole percent of the matrix metal and catalyst metal combined. 
     
     
       7. The process of  claim 6  wherein the catalytically active metal comprises from about 10 to 50 mole percent of the matrix metal and catalyst metal combined. 
     
     
       8. The process of  claim 7  wherein the catalytically active metal comprises cobalt and ruthenium and wherein the content of the catalytically active metal comprises from about 5 to 50 mole percent of the matrix metal and catalyst metal combined. 
     
     
       9. The process of  claim 8  wherein the ruthenium content is from about 0.001 to about 5 mole percent of the matrix metal and catalyst metal combined. 
     
     
       10. The process of  claim 9  wherein the matrix metal is selected from the group consisting of titanium, cerium, aluminum, a mixture of cerium and aluminum, a mixture of silicon and aluminum, and a mixture of titanium and aluminum. 
     
     
       11. The process of  claim 1  wherein the catalyst comprises one or more promoters selected from the group consisting of Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Cu, Ag, Au, Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Rh, Pd, Os, Ir, Pt, Mn, B, P, and Re. 
     
     
       12. The process of  claim 11  wherein the promoter comprises from about 0.001 to 20 mole percent of the total metal content. 
     
     
       13. The process of  claim 12  wherein the promoter comprises from about 2 to 5 mole percent of the total metal content. 
     
     
       14. The process of  claim 12  wherein the catalytically active metal is cobalt, the promoter is rhenium, wherein the combined cobalt and rhenium content is from about 10 to about 50 mole percent of the total metal, and the rhenium content is from about 0.001 to about 5 mole percent of the total metal. 
     
     
       15. The process of  claim 12  wherein the promoter is rhenium, the combined content of cobalt, ruthenium, and rhenium is from about 10 to about 50 mole percent, and the combined content of rhenium and ruthenium is from about 0.001 to 5 mole percent. 
     
     
       16. The process of  claim 14  wherein the matrix metal is selected from the group consisting of titanium, cerium, aluminum, a mixture of cerium and aluminum, a mixture of silicon and aluminum, and a mixture of titanium and aluminum. 
     
     
       17. The process of  claim 15  wherein the matrix metal is selected from the group consisting of titanium, cerium, aluminum, a mixture of cerium and aluminum, a mixture of silicon and aluminum, and a mixture of titanium and aluminum. 
     
     
       18. A process for producing hydrocarbons by contacting a feed stream comprising hydrogen and carbon monoxide with a catalyst in a reaction zone maintained at conversion-promoting conditions effective to produce an effluent stream comprising said hydrocarbons, characterized by using a catalyst prepared by a method comprising (1) forming a catalyst gel by destabilizing an aqueous colloid comprising (a) at least one catalytic metal for Fischer-Tropsch reactions, (b) at least one colloidal oxide selected from the group consisting of cerium oxide, zirconium oxide, titanium oxide and aluminum oxide, and optionally (c) at least one alkoxide selected from the group consisting of Al(OR) 3 , Si(OR) 4 , Ti(OR) 5  and Zr(OR) 4 , where each R is an alkyl group having from 1 to 6 carbon atoms; and (2) drying the gel. 
     
     
       19. The process of  claim 18  wherein the catalytic metal of (a) is a combination of cobalt and ruthenium. 
     
     
       20. The process of  claim 18  wherein the drying (2) is accomplished by vacuum drying or heating in air. 
     
     
       21. The process of  claim 18  wherein the drying (2) is accomplished by allowing supercritical fluid to flow through the gel material. 
     
     
       22. The process of  claim 18  wherein the catalyst preparation further comprises reduction treatment of the dried gel from (2).